Boggart Ram-Gang [Shadowmoor] HGSS19 the attacking monster loses 500

the attacking monster loses 500 ATK during damage calculation only

If this card Summoned this way is used as a Synchro Material Monster

Set: Battle Pack 2: War of the Giants - Round 2 Card type: Normal Trap Rarity: Super Rare Attack: 0 Defense: 0 When your opponent targets exactly 1 monster you control (and no other cards) for an attack

and Special Summon 1 "Gem-Knight" Fusion Monster from the Extra Deck

Boggart Ram-Gang [Shadowmoor] HGSS19 the attacking monster loses 500Set: Shadowmoor Type: Creature Goblin Warrior Rarity: Uncommon Cost: {R G}{R G}{R G} Haste Wither (This deals damage to creatures in the form of 1 1 counters.) "We're going to need a bigger gate." Bowen, Barrenton guardcaptain